Use of EExd cable gland for 6.6 kV XLPE cable termination in motor 2

[nirishsam]

We have purchased 6.6 kV, EEx d induction motor for one of our oil & gas client for ZONE-1 IIA, T3 area. The motor cable is XLPE insulated , 3 core , 120 sqmm, armoured, Al conductor type. We have asked for Raychem outdoor type termination (EPKT 3362). I want to know how this Raychem termination is carried out by using double compression type EExd cable gland. Most of the cable terminator in India avoid using cable gland for HV motor cable termination. Will anyone give me procedure & drawing for EExd MV motor XLPE cable termination using cable gland? I am sure that in Europe people do proper EExd cable termination for EExd motors. Thanks in advance.

 

[7anoter4]

I used Raychem terminations only for Class II Division 1 Location but I think is similar
for ZONE-1 IIA, T3 area [corresponding to Class I Division 1 acc.to NEC ]
Instruction for cable gland installation [see an example]:

http://www.drakamog.com/pdf/installation/peppers/Assembly-A2LDSF.pdf

The motor EExd is equipped with cable terminal box suitable for Raychem or Elastimold termination.
See for example ABB Flameproof Motors:

http://library.abb.com/global/scot/...on machines flameproof machines EN 062005.pdf

If the terminal box is too small and Raychem EPKT 3362 will require more room you may try
Raychem MCK-V 5-8 kV see:

http://www.nhelec.com/epd-pdf/mck.pdf

Regards

 

[nirishsam]

Thanks Zanoter-4. The last URL nhelec.com is really useful for me.
The breakout boot in EPKT 3362 is primarily for weatherproof sealing. In the Exd motors terminal box is mostly weatherproof (IP55 or IP4X) hence this breakover can be deleted to reduce around 100 mm from the total space required otherwise from gland plate. We can directly put the stress control tube & do the rest termination for EPKT 3362. Am I correct?
The core to core clearances in the terminations (phase to phase)shall be as per the voltage class as recommended by the termination kit manufacturer. I can understand that but what is the significance of the length. The length from the gland plate to the terminal bushing inside TB is governing factor. Can we get termination kits with variable lengths for one voltage class?
Is it a wrong forum for this subject. Please suggest a proper forum. I am new to eng-tips.

 

[7anoter4]

If you intend to employ EPKT 3362:
First of all you don't need the rain skirts at all. The total insulated length from the end of screen to terminal has to be
270 mm at least [for 7.2 KV].A minimum clearing to be kept from the metallic parts [see:

http://www.cableservices.co.uk/newsite/pdf_files/CS_Catalogue_LoRes.pdf

page 30]
The boot has to be inside the box and the gland is applied over the cable jacket.
To use MCK-5-8 KV only if the motor leads are not connected to the terminal mounted on insulator, but they are free [only a lug is provided at the free end of the lead and no terminal]
I don't know if it is a more specific forum close to this subject
Regards

 

[samanele]

We have almost similar problem in Siemens AG make (type 1MA4 316) Exe 6.6 kV motor. The clearance inside TB, from terminal to gland plate is very less (around 190 mm). As written by Zanoter-4, Raychem kit like EPKT needs minimum 270 mm from the screen end to terminal. Can anyone explain why this minimum limit? Does voltage gradient (from terminal to screen)or stress control require this much clearance? What is the problem if we reduce it to say 150 mm for 6.6 kV? (Which is more than required phase to earth clearnace in air for 6.6 kV)
One probable solution we are thinking of is to use compound filling (like Guroflex MV). What can be the ideal solution for cable termination in above Siemens AG make motor?

 

[7anoter4]

As I understood from the follows link:

http://www.cableservices.co.uk/newsite/pdf_files/Catalogue_Page36.pdf

by using Raychem insulation boots on terminals one may reduce up to 150 mm [270-150=120 mm so 190 mm would be ok].
I didn't use this boots so I think you have to contact Raychem prior to order this.
For other Raychem accessories see:

http://www.cableservices.co.uk/newsite/pdf_files/

Regards

 

[samanele]

Thanks Zanoter-4.
However I couldnt find the information that one may reduce the clearance from terminal to screen end by 150 mm by using boots.
The boots are recommended where terminal to terminal (phase to phase) & terminal to ground/TB body are less than specified clearances in air for applicable voltage class. In our Siemens motor those clearances are acceptable.
Probably I am not able to understand your point. Please explain.
Regards

 

[7anoter4]

You are right use of "extension glands" may add an extension [out of the terminal bottom plate].
The extension gland however, I am not sure,if it is suitable for hazardous location.

 

[Welshdai]

I need to change the direction of an 6.6Kv motor.
The cable is too short to change in the normal way. So can this be done without compromise to the terminals at the rear of the terminal posts. I do not know how the inner connection is brought out to the posts.

 

[ScottyUK]

You should start a new thread for a new question, but have you looked at swapping at the source end? Most switchgear has the outer poles roughly symmetrical about the cable entry point.

Internally the motor will likely be bars if it is a big one, and flexible (semi-flexible) for a small one. You need to provide more info. A good rewind shop would give you an answer pretty quickly.


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If we learn from our mistakes I'm getting a great education!

 

[Welshdai]

Thanks for the comment, yes the source end was not an option as the terminals are in line top to bottom,
we have now sorted the motors by removing the terminal post and swapping at the back on the inside of the motor.
(there,s plenty of room).
Regards